Relocation of nests by swarms and nest reconstruction in late autumn in the primitively eusoical wasp,Ropalidia fasciata,with discussions on the role of swarming

FourRopalidia fasciata colonies abandoned their nests without any sign of predator attack, heavy parasitism or damage due to typhoon or man, and established new nests by groups. At least 1, possible 3, of them can be difined as the nest relocation by a swarm, since the cell contents were considered to be removed before the nest abandonment. This method of nest foundation in a primitively eusocial species is considered to be an intermediate stage between nest foundations by idependent-founding, primitively cusocial species and swarm-founding, highly eusocial species (subgenusIcarielia) in the genusRopalidia. Some nests were established in October, near the last stage of ordinary colony cycle of this species. The significance of these facts in relation to West-Eberhard's polygynous family hypothesis (1978) is discussed.